Electrical timing device



Feb. 16, 1932. R. J. WISE 1,845,993

ELECTRICAL TIMING DEVICE Filed Aug. 27, 1929 Patented Feb. 16, 1932UNITED STATES PATENT OFFICE RALEIGH J. WISE, OF PLAINFIELD, NEW JERSEY,ASSIGNOR TO THE WESTERN UNION TELEGRAPH COMPANY, OF NEW YORK, N. Y., ACORPORATION OF NEW YORK ELECTRICAL TIMING DEVICE Application filedAugust 27, 1929. Serial No. 388,737.

' This invention relates to an electrical timing device and moreparticularly to a device for operating an instrument such as a telegraphrelay in response to a predetermined 5 time interval of current flow.

The invention is especially adaptable to the operation of a call signalat a distant station of a telegraph system employing simplex printerswhere it is desirable, in order to save wear on the printing machines,eliminate noise and conserve on the current consumption of the machines,to maintain the driving motors idle when the circuit is not inoperation. but to have the printing unit quickly available when it isdesired to transmit thereto.

In a patent to Rothermel and Hewitt, No. 1,803,304. granted April 28,1931, there is described a call system for a simplex tele- 0 graphsystem, in which the call signal is operated by a single open circuitcondition of the line, the call signal responding irrespective of thelength of time the open circuit condition is maintained. While thissystem 5 has proven highly satisfactory, there are certain installationsin which so called concen-' tration units are employed, to which thesystem is not well adapted since there is an open circuit condition ofthe line of from one to a two seconds, produced when the concentrationoperator detaches the plug from the line jack. which causes a false callsignal to be established.-

This difficulty has been overcome in a system disclosed in anothercopending application of W. B. Blanton, filed August 3, 1929, Serial No.383235, in which the signal is made responsive to an open circuitcondition of short duration but is immediately discontinued, if the opencircuit condition continues, as for instance, for a period exceedingabout one third of a second.

It is one of the objects of my invention to overcome this same difliculty by providing a call signal which does not respond to an opencircuit condition of short duration but only to one of prolongedduration, as for instance, several seconds.

Another object is to provide apparatus for causing the sounder or therecording or printto provide an apparatus responsive to a predeterminedaccumulated time of applied potential.

Other objects and advantages will hereinafter appear.

In accordance with my invention I employa-condenser having a slowcharging rate in connection with a gaseous conduction device having adefinite breakdown potential, the condenser being bridged across thegaseous conduction device so that after a predetermined period ofcurrent flow the condenser accumulates a charge equal to the breakdownpotential of the gaseous conduct-ion tube and dischargestherethrough,-the discharge continuing until the charge is reduced tothe lower limit of the operating voltage of the tube, at which time thedischarge is discontinued abruptly. A relay, call signal, countingmechanism or other form of electrically operated device may be connectedin series with the gaseous conduction device so as to be operated whenthe discharge occurs and a locking circuit may be provided for theelectrical device to continue the operation thereof after the dischargehas ceased.

The charging current may be applied continually or intermittently. Inthe latter case the condenser acquires its charge over the accumulatedtime of current flow thereto.

In the preferred embodiment of the invention I employ the timing devicein a telegraph system for operating a call'signal at a distant stationin response to a prolonged pulse of definite polarity or to a prolongedopen circuit condition of the line, to call the attendant and/or tocause a normally inactive sounder or recording device to respond to thetransmitting signals.

The invention will be more fully understood by reference to theaccompanying drawings in which: I

Figure 1 is a circuit diagram embodying the invention, illustrating anarrangement for obtaining a delayed operation of an electrical apparatusin response to the operation of a circuit closing contact;

Figure 2 is a circuit diagram showing the invention applied to a simplextelegraph system for operating a call signal;

Figure 3 is a circuit diagram of the invention applied to a soundersilencer;

Figure 4 is a circuit diagram showing an arrangement for obtaining theaccumulative effect of an intermittent current; and

Figure 5 illustrates an arrangement for regulating the rate of chargingof the timing condenser.

Referring to Figure 1, I have shown a circuit havlng, in series, agenerator 10, a high resistance 11, a resistance 12, a gaseousconduction device 13, the winding 14 of a relay 15, and a switch 16. Acondenser 17 is bridged across the'resistance 12, gaseous conductiondevice 13 and relay 15.

The gaseous conduction device 13 may consist of a pair'of opposedclosely spaced electrodes 18 and 19 contained within a sealed envelopefilled with one of the monatomic gases such as neon, argon or helium ormixtures thereof, the pressure of the gas and spacing of the electrodesbeing such that the device will have a definite starting or breakdownpotential, preferably of from 100 to 200 volts, and a considerably loweroperating voltage.

It is a characteristic of negative glow tubes of this nature, when theelectrodes are thoroughly degasified and cleaned and pure gas employed,to have an extremely uniform starting or breakdown potential over a longperiod of time, particularly when operated at low current discharges,and after the discharge has been initiated therethrough, to continue toconduct current until the voltage has decreased considerably below thevalue required to start the discharge.

The voltage delivered by the generator 10 through the resistance 11 isbelow the start-- mg or operating voltage of the tube 13 so that uponclosing the switch 16 no dischar e will occur therethrough. Thecondenser 1 however, gradually assimulates a charge over an interval oftime depending upon the capacity of the condenser and the value of theresistance 11, until it reaches the breakdown otential of the tube 13.The condenser then ischarges through the tube and energizes the windingof the relay 15. The discharge continues until the voltage has decreasedto the lower limit of the operating voltage of the tube and is thenabruptly discontinued. The rate of discharge may be regulated by theresistance 12.

discharge ceases, a locking circuit for the relay may be provided fromthe generator 10 through a resistance 21, a second contact 22,

of the relay 15, winding 14 and back to the generator, by way ofconductor 23. The locking circuit will thus be established during thedischarge by closing'of the contact 22 and is broken manually by theswitch 24. It will be appreciated that the condenser 17 will charge upand discharge periodlcally through the tube 13,: and if the lockingcircuit be omitted, the discharge will produce an intermittent operationof the relay 15. Due to the uniform electrical characteristic of thedischarge tube, the time rate of charging and discharging may be madevery uniform.

Either the resistance 11 or the condenser 17, or both maybe variable topermit the rate of charging to be regulated so as to obtain the desiredtime interval between the closing of the switch 16 and the operation ofthe relay 15. The switch 16 is shown as electro-magnetically operatedand may constitute the contacts of a relay operated by a telegraphsignal, as for instance, to operate a call system. 7 V

In Figure 2, I have illustrated, such a call system applied to a simpletelegraph circuit including a receiving or line relay 25 con-- callyconnected with relation to the generator 10 exactly as described inconnection with Figure 1. The front contact 33 of the relay 25 isconnected throu h a low resistance 34 to the side of the con enser 17opposite that to which the relay tongue 30 is connected.

The contact 20 controls a call signal circuit including a battery 35 anda signal device 36, which may be either visible or audible.

The operation of the call system is as follows:

When the line is idle and no signals are being transmitted the relaytongue 30 rests against the front contact 33 and the circuit to thegenerator 10 is open, the condenser 17 at the same time being shortcircuited through the'low resistance 34.

When signals are transmitted the relay tongue alternately engages thefront and back contacts 31 and 33. Upon contact with the back contactthe circuit to the relay 32 is closed and at the same time chargingcurrent is delivered to the condenser 17. However, the relay tongue doesnot remain on its back contact for a suflicient period to charge thecondenser to the breakdown potential of the tube 13 and on its return tothe front contact, the condenser discharges through the resistance 34.Therefore, the condenser does not accumulate any appreciable chargeduring the normal transmission of signals.

If, however, the transmitting operator desires to call the attendant atthe distant station he holds the line open for a prolonged interval,sayfrom fifteen to twenty seconds, so as to retain the relay tongue on itsback contact 31 for a period suflicient to charge the condenser to thebreakdown potential of the tube, at which time a discharge occursthrough the tube and effects the operation of the call signal 36 throughthe relay 15. The relay 15 is locked up until manually released by theopening of the switch 24.

In duplex, quadruplex or single line repeater sets, etc. it is oftendesirable that the sounder at the repeating station remain silent exceptwhen it is necessary to call the attendant as for testing of the circuitor for the reception of a message, and in Figure 3 there is illustrateda system for automatically closing local circuits at the repeatingstation, in response to a prolonged open condition of the line, forcausing the sounder to respond to subsequent signals made at the callingstation.

A leak relay 37, having a front contact 38 and a back contact 39, isconnected between the line and the ground to respond to the signalstransmitted from the calling station.

The time relay circuit includes the generator 10 and high resistance 11in series with the condenser 17 and the gaseous discharge tube 13 andrelay 15 bridged across the terminals of the condenser. The contact 22of the relay controls a locking circuit for the relay 15 through asecond generator 40, resistance 21 and manual switch 24. The contacttongue 41 of the relay 15., when in engagement with the front contact42, com pletes a circuit for a sounder or other rereiving apparatus 43,from the generator 10, through the contacts of the leak relay 37. Theback contact 44 of the relay 15 completes a short circuit of the highresistance 11 and generator 10, when the leak relay armature is on thefront contact.

The operation of the system is as follows: During the period when theline is idle, and the contact 38 closed by the steady line cur rent, thecondenser 17 is discharged through the low resistance 45. contacts 44and 38 of relays 15 and 37. The generator. is short circuited throughthe same contacts and no charging of the condenser occurs. If signalsare transmitted, the relay 37 responds thereto but since the contact 42of relay 15 is open the sounder does not operate. When the armature ofthe leak relay 37 is on the back contact, the condenser tends to chargeup but since this position is not maintained for a sufficiently longperiod to discharge through the tube 13 the relay 15 remainsunenergized. Each time the armature reengages the front contact 38 thecondenser discharges. If the transmitting operator (lesires to call therepeater station he holds the line open for a prolonged period, thusmaintaining the armature of the leak relay on its back contact for asufficientperiod to charge up the condenser 17 to enable it to dischargethrough the tube 13 and relay 15 whereupon the contact 22 is closed tocomplete the relay locking circuit and contact 42 is closed to completethe sounder circuit. The sounder 43 will then respond to the linesignals until its circuit is broken by opening of the switch 24 andde-energizing the relay 15.

In Figure 4 I have shown an arrangement adapted to respond to theaccumulated time durin which the relay tongue remains on either 0% itscontacts, to operate the relay 15. The contacts 31 and 33 of the relay25 are connected to two switch contacts 46 and 47 adapted to beselectively engaged by a switch arm 48. The contact 20 of relay 15 maycontrol the circuit to a counting device 49. A key 50 is bridged acrossthe plates of the condenser 17.

With the switch arm 48 on contact 46, for instance, the condenser 17will acquire a charge each time the relay tongue engages the relaycontacts 33, and since no discharge path is provided for the current ineither position of the relay, other than through the tube 13, thecondenser will gradually acquire a charge of sufficient voltage to breakdown the resistance of the tube and discharge therethrough, thus causinga momentary flow of current through the relay 15 whereby the countingmechanism 49 will be operated.

Since the accumulated time required to charge the condenser is constant,irrespective,

of the length or frequency of the individual time intervals of which itis composed, the total interval between successive discharges will givea measurement of the proportion of the time the tongue rests on each ofits contacts.

This embodiment is useful in determining the natural bias of a relay.For instance, if current reversals of uniform periodicity are impressedupon the winding of a polar relay the relay tongue should rest forexactly equal intervals upon each of the contacts. Due to a natural biasof the relay tongue in one direction, however, the period of engagementwith one contact may be slightly greater than that with the oppositecontact. I By utilizing the relay to be tested in place of the relay 25and placingthe switch arm 48 first on contact 46 and measuring the timerequired for the discharge to occur and then repeating the measurementwith the switch arm on the contact 47 the direction of the bias may bereadily determined, since the bias causes the contact tongue tohold-over on one contact slightly longer than on the other, and thereby,increases the chargin rate of the condenser in one position of t eswitch 48. The condenser 17 should be completely discharged before eachmeasurement, by closing the switch 50.

In Figure 5 a leak resistance 51 has been placed in shunt to thecondenser 17 to permit the charge to leak oif slowly and thus prolongthe charging period of the condenser. If the leakage rate is made justequal to the charging rate for the average condition of operation of therelay 25 in response to telegraph signals, the condenser will neveracquire suflicient charge to operate the tube 13. However, if for anyreason the relay tongue remains on contact 52 for a greater proportionof the time, the condenser will charge up and discharge through the tube13 to operate the relay 15 and thus indicate the existence of suchcondition.

Various other applications of the invention will occur to those skilledin the art and I desire to include, within the scope of my invention,all such modifications as come within the terms of the appended claims.

What is claimed is:

1. A telegraph call system comprising a reage.

lay responsive to line conditions, a condenser, means for charglng saidcondenser 1n one pod sition of said relay, means for discharging saidcondenser in the other position of said relay, a gaseous dischargedevice having a definite break down voltage and a lower operatingvoltage connected across said condenser to provide a discharge path whenthe charge on the condenser equals said breakdown voltage.

- lay responsive to line conditions, a condenser,

3. A telegraph call system comprising a remeans for charging saidcondenser in one position of said relay, means for discharging saidcondenser in other position of said relay,

a gaseous discharge device having a definite breakdown potential and alower operating potential connected across said condenser to provide adischarge path when the charge on tial, and means for regulating therate of charging of said condenser.

4. A telegraph call system comprising a relay responsive to lineconditions, a condenser, means for charging said condenser in oneposition of said relay, means for discharging said condenser in theother position of said relay, a gaseous discharge device having adefinite breakdown potential and a lower operating potential connectedacross said condenser to provide a discharge path when the charge on thecondenser equals said breakdown potential, a relay in series with saidgaseous discharge device, a call signal circuit closed by said relaywhen said condenser discharges through said gaseous discharge device andmeans for maintaining said call circuit closed after the dischargethrough the device ceases.

5. In a telegraph system, a receiving relay, a receiving instrument, acircuit for said receiving instrument, a condenser, a gaseous conductiontube bridged across said condenser,- a leakage path around said tube,said receiving relay in one position rendering said leakage pathineflective, and permitting said condenser to charge at a slow rate,means for causing said condenser to discharge through said tube after ithas acquired a predetermined charge, and normally maintaining thecircuit of saidreceiving instrument open, said relay being operated bythe discharge current through said device to close said circuit, andrender the receiving instrument responsive to the receiving relay.

6. A relay timing device comprising a condenser, means for charging saidcondenser at a slow rate, means for continuously discharging saidcondenser at a rate less than the charging rate, a gaseous conductiondevice connected across the terminals of said condenser and a relay inseries with said gaseous conduction device and condenser, said condenserafter it has acquired'a predetermined charge discharging through saiddevice and no energizing said relay. Y

7. A relay timing device comprising a c011- enser, means responsive tocurrent of one polarity for charging said condenser at a slow rate, saidcondenser being non-responsive to 1 the accumulative effect of spacedimpulses of said polarity, a gaseous conduction device connected acrossthe terminals of said condenser and a relay in series with said gaseousconduction device, said condenser, after it has acquired a predeterminedcharge discharging through said device and energizing said relay, and alocking circuit for said relay for maintaining the same energized aftersaid discharge has ceased. 12

8. A relay timing device comprising a condenser, means for charging saidcondenser at a slow rate, a gaseous conduction device connected acrossthe terminals'of said condenser and a relay in. series with. saidgaseous con- 13o duction device, said condenser, after it has acquired apredetermined charge discharging through said device and energizing saidrelay, and means for controlling the. rate of discharge through saiddevice.

9. A telegraph system comprising a relay responsive to line signals ofmarking and spacing character, a condenser arranged to be charged duringthe reception of a signal of one character and to be discharged duringthe reception of a signal of the other character and circuit closingmeans controlled by the discharge current of said condenser, after thecondenser has acquired a predetermined charge.

10. A telegraph system comprising a line circuit, a source of linesignals of marking and spacin character, a condenser associated withsaid clrcuit and arranged to be charged during the period of a signal ofone character and to be discharged during the period of a signal of theopposite character and means in shunt to said condenser having anormally high resistance and a definite break down voltage to provide adischarge path for the condenser after it has acquired a predeterminedpotential and circuit controlled means in said discharge path.

11. A telegraph system comprising a line circuit, a source of linesignals of markin and spacing character, a condenser associated withsaid circuit and arranged to be charged during the period of signal ofone character and to be discharge during the period of a signal of theopposite character and means in shunt to said condenser having anormally high resistance and a definite break down voltage to provide adischarge path for the condenser after it has acquired a predeterminedpotential, the capacity of said condenser and the charging rate thereofbeing so proportioned that the condenser will not attain said break downvolta e in response to ordinary telegraph signals 0 mixed marking andspacing character.

12. A telegraph system comprising a line circuit, a source of signals ofmarkin and spacing character, a condenser associate with said circuitand arranged to be charged during the period of a signal of spacingcharacter and to be discharged during the period of a signal of markingcharacter, a glow discharge tube in shunt to said condenser to provide adischar e path for the condenser after it has acquire a predeterminedpotential, the capacity of the condenser and the charging rate thereofbeing so proportioned that the condenser will not attain the break downvoltage of the low tube in response to ordinary telegraph signals ofmixed marking and spacing character and circuit controlled means in saiddischarge path.

13. A telegraph system comprising a line circuit, a source of signals ofmarking and spacing character, a condenser associated with the circuit,a glow tube in shunt to the condenser, means for chargin the condenserin response to signals of a de ite character, said condenser in responseto ordinary telegraph signals of mixed marking and spacing characterbeing restricted to a potential below the break down voltage of the glowtube and being chargeable to a potential above said break down voltagein response to prolonged signals of said definite character.

14. In a telegraph system, a line, a relay responsive to line signals ofmarking and spacing character, a receiving instrument normallydisassociated from the line, a condenser responsive to prolonged signalsof one character for acquiring a predetermined charge, said condenserbeing non-responsive to regular telegraph signals of mixed marking andspacing character and means actuated by the discharge current of saidcondenser after it has acquired said predetermined charge, foroperatively associating the receiving instrument with the line.

In testimony whereof I afiix m signature. RALEIGH WISE.

